IRVING, Texas -- After every game, Stephen McGee can count on text messages from his mother and his fiancée.

On Saturday night, McGee's iPhone had quite the workout.

"Normally there's a little red number with how many new texts you got," McGee said. "It ended up going to an exclamation point, so quite a few."

The limits of McGee's iPhone figure to be tested once again with him more than likely making the first start of his career Sunday at Philadelphia.

Jon Kitna has a left oblique strain that leaves him doubtful at best to play against the Philadelphia Eagles. Kitna will start if he's healthy, but why would the Dallas Cowboys have signed Chris Greisen to the practice squad if they felt Kitna would be good to go?

Stephen McGee's demeanor against the Cardinals during his first NFL game impressed the Cowboys. AP Photo/Paul Connors

The Cowboys would be the ninth team forced to use three different starting quarterbacks this season, joining Tennessee, Pittsburgh, Miami, Detroit, Cleveland, Carolina, Arizona and Minnesota. The Pittsburgh Steelers are the only team among the group to make the playoffs, going 3-1 during Ben Roethlisberger's suspension with Dennis Dixon and Charlie Batch as the starters.

Life has not been easy for No. 3 quarterbacks this year.

The only third-stringers to win their first starts were the last two to have a chance, Arizona's John Skelton on Dec. 12 and Minnesota's Joe Webb on Tuesday. Miami's Tyler Thigpen, Cleveland's Colt McCoy, Tennessee's Rusty Smith and Detroit's Drew Stanton combined for two touchdowns, five interceptions and nine sacks in their first starts that were lost by an average of 11.6 points to Chicago (twice), Houston and Pittsburgh.

Cowboys interim boss Jason Garrett knows what McGee is facing more than most head coaches. Garrett's first start came Nov. 14, 1993, against the Phoenix Cardinals when he completed just 2-of-6 passes for 25 yards before newly signed Bernie Kosar took over after three series.

"What we liked about [McGee] was his demeanor," Garrett said. "He didn't really blink. He was 'OK, coach, I got it. I got the calls. I can handle this stuff.' And he showed us that and as the game wore on he got more comfortable."

Philadelphia would not be the ideal opponent for a first start, but McGee has been in the quarterbacks' room preparing for the Eagles' defense four times in two seasons. He might not have seen Philadelphia's array of blitzes live before, but he has some idea about the personnel.

If time and effort mean anything, then McGee should be ready.

"I purposely got my rent house a two-minute drive from here [the team's training facility], a couple of stop signs, right off Cowboys Parkway," McGee said. "I did that with the sole intention that I could hang out here as much as I possibly can and be a rat around this place, listen and watch and learn and ask as many questions as I can when at all possible."

McGee's outing against Arizona was far from perfect. At times he made reads on throws too quickly; at others, too slowly. But he made enough plays for the Cowboys to be in position to beat the Cardinals, including the 37-yard touchdown pass to Miles Austin with 1:41 to play that gave Dallas a 26-24 lead.

This week, McGee will benefit from actually taking first-team reps in practice. He put his snap total with the No. 1 offense at three in his two years. Most of his throws to Austin have come in pregame warmups. Until Saturday, he had thrown as many passes to Jason Witten as you and I have.

"There's things to learn about everybody," McGee said. "Everybody is just a little bit different. ... I don't think it's something that's going to happen in one week, but it certainly can be a lot better."

This would be McGee's first start since Sept. 27, 2008, against Army in his senior season at Texas A&M. He completed 7-of-9 passes for 109 yards and a touchdown before injuring his right shoulder.

"Every chance you do get is a huge opportunity," McGee said. "You send that video out to the whole league. Everybody sees it. Everybody takes notice. It's basically a resume for the NFL. It's definitely an opportunity that if I do get, I want to make the most of and show people what I can do."

Todd Archer covers the Cowboys for ESPNDallas.com. You can follow him on Twitter or leave a question for his mailbag.